Di Felice gives 'Winawer, Szymon Abramowicz' at this event, and Kingston seems to accept this in his review of Di Felice's book, but Kingston also mentions (in another article, on Winawer himself, also at ChessCafe) that Winawer had many chess-playing brothers, and given the low score against unknown players at this event, it seems more likely that the Winawer here was one of the brothers.